Concrete Garage Floor Repair in Naperville

Every concrete floor cracks. Concrete shrinks as it dries, about a sixteenth of an inch for every ten feet, and the saw-cut joints in your floor are there to give that shrinkage a straight line to follow. When a crack shows up somewhere else, the question is whether it is shrinkage that missed the joint or the ground letting go under the slab.

Hairline cracks and surface crazing

Thin cracks that stay flat and stay the same width are shrinkage. So is crazing, the fine spiderweb pattern some troweled floors show. Crazing rarely runs deeper than an eighth of an inch and it doesn't weaken the slab. These usually need nothing. Fill them if salt water collecting in them bothers you, or leave them alone.

A crack with one side higher

Run your shoe across it. If one side sits higher, the slab has stopped being one piece and one of the pieces has moved. That isn't shrinkage. Something under the floor settled or heaved. For a number to measure your own floor against, one state's new-home warranty rule draws its line at a quarter inch, of width or of height difference.

A crack that keeps getting wider

Mark the ends with a pencil and write the date next to them. A crack that opens and closes a hair with the seasons is living with the weather. One that is longer or wider next spring is being pulled by what's happening underneath, and filling it won't stop that.

How garage floor crack repair is done

A crack that has stopped moving gets routed, meaning opened up along the top with a grinder, then cleaned and filled. A crack that still moves needs a flexible sealant, so it works like a joint and keeps water out. That seal adds no strength. Rigid epoxy in a moving crack is usually money gone, because the concrete tends to crack again right beside the repair.

Garage floor crack repair on a quiet crack is a small job, and plenty of homeowners do it themselves. Cracks in a patio, a walk or another outdoor slab read much the same way, and our concrete repair guide covers those.

The pits are almost always under where the car sits. Slush packed in the wheel wells melts onto the floor, the salt water soaks into the top of the slab, and on a cold enough night it freezes. Water grows about 9 percent when it turns to ice. Repeat that all winter and the surface starts coming off in flakes, then in pits.

There is a lot of salt to bring home. The City of Naperville has averaged 11,400 tons of road salt a year over the past ten years, and that is before Route 59 and Ogden Avenue, which state crews salt on their own.

The flaking has a trade name, scaling, and it hits hardest on floors poured without air-entrained concrete, the kind with microscopic bubbles that give freezing water somewhere to go, or troweled while water was still sitting on the surface.

What helps, cheapest first: hose the floor down when the weather breaks so the salt doesn't sit there until April, keep deicer off new concrete for its first winter, and put a penetrating silane or siloxane sealer on a floor that is still sound. The sealer makes the surface shed water. It wears off and has to be redone every several years, and it will not fix a floor that has already started to pit.

A garage floor isn't part of the foundation. It is a slab poured inside the foundation walls, sitting on whatever fill the builder put there. Where the fill went in loose and deep, the floor follows it down for years.

About two thirds of Naperville's homes were built in the 1970s, 80s and 90s, so a lot of these floors are decades into that settling. Water speeds it up. A downspout emptying at the garage corner is the first thing we look for, and the city's own guidance is to let sump water out at least 10 feet from the house.

Garage floor leveling: when lifting a slab works

Garage floor leveling, also called slab lifting, mudjacking or foam jacking, means drilling holes in a settled slab and pumping grout or expanding foam underneath to raise it. It suits a slab that sank in one piece and is otherwise sound. It does not fix why the floor sank, and on a slab that is already broken, replacement is the better money. We don't lift floors. If yours is a good candidate, we'll tell you to call someone who does. For walks, patios and driveways, our concrete leveling guide compares the methods and what they cost.

Cutting out and repouring a failed garage floor section

When the slab has cracked into pieces that sit at different heights, the repair is to take the failed part out. We saw-cut along the existing joints so the new piece is a clean rectangle, break out the bad panel, dig out and recompact what's under it, and pour back with the new concrete isolated from the foundation wall. Done right, it sits flush and lines up with the joints like one more panel in the floor. It will not match the color of the old concrete around it.

Garage floor heaving at the door and apron

The opposite problem shows up at the overhead door. The apron, or the first few feet of floor, rises in January and drops back in spring. That is frost in wet ground lifting the slab. The fix, for the floor or for a garage apron repair, is drainage and a proper stone base under a new section. Filler in the crack it leaves does nothing.

For garage floor repair in Naperville, the city has no written rule that names garage floors, and its permit portal has no application by that name. Here is how it works in practice. Naperville's permit guide says cosmetic improvements don't need a permit and that a homeowner may do most ordinary repairs without one, and we read crack filling and sealing as falling there. Replacing the floor is different. The city's own issued-permit reports show garage floor replacements going through the residential Driveway/Sidewalk/Stoop permit, with a slab inspection on the job.

We file that permit and schedule the inspection as part of the work, and the cost is inside the quote. Section repairs fall between the two, so we check with the city before we cut.

The building code's garage section says how the floor has to drain, and it is worth knowing when you're judging old work. The parking area has to slope so liquids run to a drain or toward the vehicle door. Naperville adopted that rule as written and has added no garage floor rules of its own. If meltwater on your floor runs to the back wall or sits in a low spot, the slab was poured wrong or it has moved since.